Because of their thermal stability, perfluorinated polyalkylether fluids possess a great potential for use as engine oils, hydraulic fluids and greases. However, a serious drawback in their use results from the fact that metals, e.g., certain ones present in aircraft engine components, are corroded at temperatures above 550.degree. F. in an oxidative environment. For example, when the fluids are employed as lubricants for mechanical components composed of mild steels, corrosion has occurred at temperatures of from 550.degree. to 600.degree. F.
In U.S. Pat. No. 4,043,926, C. E. Snyder, Jr., and C. Tamborski disclose that perfluoroalkylether substituted aryl phosphines are effective as anticorrosion additives for perfluorinated polyalkylether fluids. It would be desirable to provide alternative additive materials that would be capable of inhibiting the tendency of such fluids to corrode metals at elevated temperatures.
It is a principal object of this invention, therefore, to provide an improved lubricant composition which contains, as the base fluid, a perfluorinated polyalkylether.
Another object of the invention is to provide a lubricant composition that is substantially non-corrosive to ferrous and titanium alloys.
Other objects and advantages of the invention will become apparent to those skilled in the art upon consideration of the accompanying disclosure.